13278731 has 4 divisors (see below), whose sum is σ = 13368000. Its totient is φ = 13189464.

The previous prime is 13278721. The next prime is 13278737. The reversal of 13278731 is 13787231.

13278731 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 13278731 - 2⁶ = 13278667 is a prime.

It is a super-2 number, since 2×13278731² = 352649393940722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13278737) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44411 + ... + 44708.

It is an arithmetic number, because the mean of its divisors is an integer number (3342000).

Almost surely, 2^13278731 is an apocalyptic number.

13278731 is a deficient number, since it is larger than the sum of its proper divisors (89269).

13278731 is an equidigital number, since it uses as much as digits as its factorization.

13278731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89268.

The product of its digits is 7056, while the sum is 32.

The square root of 13278731 is about 3643.9993139407. Note that the first 3 decimals coincide. The cubic root of 13278731 is about 236.8020863110.

The spelling of 13278731 in words is "thirteen million, two hundred seventy-eight thousand, seven hundred thirty-one".